Treatment of dental biofilm-forming bacterium Streptococcus mutans using tannic acid-mediated gold nanoparticles.

Biosynthesized gold nanoparticles (AuNPs) are highly attracted as a biocompatible nanodrug to treat various diseased conditions in humans. In this study, phytochemical tannic acid-mediated AuNPs (TA-AuNPs) are successfully synthesized and tested for antibacterial and antibiofilm activity against dental biofilm-forming Streptococcus mutans biofilm. The synthesized TA-AuNPs are appeared as spherical in shape with an average size of 19 nm. The antibacterial potential of TA-AuNPs was evaluated using ZOI and MIC measurements; while, antibiofilm efficacy was measured by checking the eradication of preformed biofilm on the tooth model. The ZOI and MIC values for TA-AuNPs are 25 mm in diameter and 4 µg/mL, respectively. The MTT assay, CLSM, and SEM results demonstrate that the preformed S. mutans biofilm is completely eradicated at 4xMIC (16 µg/mL) of TA-AuNPs. Finally, the present study reveals that the synthesized TA-AuNPs might be a great therapeutic drug to treat dental biofilm-forming bacterium S. mutans.

The effect of bovine trypsin on dental biofilm dispersion: an in vitro study.

To investigate the degradation effect of bovine trypsin on multispecies biofilm of caries-related bacteria and provide an experimental foundation for the prevention of dental caries. Standard strains of S. mutans, S. sanguis, S. gordonii, and L. acidophilus were co-cultured to form 24 h, 48 h, and 72 h biofilms. The experimental groups were treated with bovine trypsin for 30 s, 1 min, and 3 min. Morphological observation and quantitative analysis of extracellular polymeric substances (EPS), live bacteria, and dead bacteria were conducted using the confocal laser scanning microscope (CLSM). The morphological changes of EPS and bacteria were also observed using a scanning electron microscope (SEM). When biofilm was treated for 1 min, the minimal inhibitory concentration (MIC) of bovine trypsin to reduce EPS was 0.5 mg/mL in 24 h and 48 h biofilms, and the MIC of bovine trypsin was 2.5 mg/mL in 72 h biofilms (P < 0.05). When biofilm was treated for 3 min, the MIC of bovine trypsin to reduce EPS was 0.25 mg/mL in 24 h and 48 h biofilms, the MIC of bovine trypsin was 1 mg/mL in 72 h biofilm (P < 0.05). The ratio of live-to-dead bacteria in the treatment group was significantly lower than blank group in 24 h, 48 h, and 72 h multispecies biofilms (P < 0.05). Bovine trypsin can destroy multispecies biofilm structure, disperse biofilm and bacteria flora, and reduce the EPS and bacterial biomass in vitro, which are positively correlated with the application time and concentration.

Vesicular Messages from Dental Biofilms for Neutrophils.

The encounter between dental biofilm and neutrophils in periodontitis remains elusive, although it apparently plays a crucial role in the periodontal pathology and constitutes a key topic of periodontology. Dental biofilm and neutrophils were isolated from orally healthy persons and patients with periodontitis. We investigated biofilm and its particle-shedding phenomenon with electron microscopy and nanoparticle tracking analysis (NTA); biofilm shedding-neutrophil interactions were examined ex vivo with epi-fluorescence microscopy. For this purpose, we used acellular dental biofilm shedding, purified lipopolysaccharide (LPS), and phorbol 12-myristate 13-acetate (PMA) as activators, and the interleukin 8 receptor beta (CXCR2) inhibitor and the anti-interleukin 8 receptor alpha (CXCR1) antibody as modulators. The shedding of acellular dental biofilms overwhelmingly consists of bacterial extracellular vesicles (BEVs). The latter induced the moderate formation of neutrophil extracellular traps (NETs) in orally healthy subjects and a strong formation in patients with periodontitis. A CXCR2 inhibitor and an anti-CXCR1 antibody had a minor effect on NET formation. Neutrophils from patients with periodontitis exhibited NET hyper-responsiveness. BEVs were stronger inducers of NET formation than purified LPS and PMA. A plateau of neutrophil responsiveness is reached above the age of 40 years, indicating the abrupt switch of maladaptive trained immunity (TI) into the activated modus. Our results suggest that dental biofilms consist of and disseminate immense amounts of outer membrane vesicles (OMVs), which initiate NET formation via a non-canonical cytosolic LPS/caspase-4/11/Gasdermin D pathway. This modus of NET formation is independent of neutrophil elastase (NE), myeloperoxidase (MPO), peptidylarginine deiminase 4 (PAD4), and toll-like receptors (TLR). In periodontitis, the hyper-responsiveness of neutrophils to BEVs and the increased NET formation appear to be a consequence of TI.

Efficacy of flossing and mouth rinsing regimens on plaque and gingivitis: a randomized clinical trial.

BACKGROUND: To investigate the effects of combinations of mechanical (brushing and flossing) and chemotherapeutic regimens which included essential oils (EO) non-alcohol and alcohol-containing mouthrinses compared to brushing only in the prevention and reduction of plaque, gingivitis, and gingival bleeding. METHODS: This was a randomized, virtually supervised, examiner blind, controlled clinical trial. Following informed consent and screening, subjects (N = 270) with gingivitis were randomly assigned to one of the following regimens: (1) Brush Only (B, n = 54); (2) Brush/Rinse (EO alcohol-containing mouthrinse) (BA, n = 54); (3) Brush/Rinse (EO non-alcohol containing mouthrinse) (BZ, n = 54); (4) Brush/Floss (BF, n = 54); (5) Brush/Floss/Rinse (EO non-alcohol containing mouthrinse) (BFZ, n = 54). Unflavored waxed dental floss (REACH unflavored waxed dental floss), and fluoridated toothpaste (Colgate Cavity Protection) were used. Examinations included oral hard and soft tissue, plaque, gingivitis, gingival bleeding, probing depth and bleeding on probing. RESULTS: After 12 weeks, both BA and BZ and the BFZ group were superior in reducing interproximal plaque (30.8%, 18.2%, 16.0%, respectively), gingivitis (39.0%, 36.9%, 36.1%, respectively), and bleeding (67.8%, 73.6%, 79.8%, respectively) compared to B. The BF group did not provide significant reductions in interproximal plaque but did reduce interproximal gingivitis (5.1%, p = 0.041) at Week 4 and bleeding at Weeks 4 and 12 (34.6%, 31.4%, p < 0.001 respectively) compared to B. The BFZ group did not significantly reduce interproximal plaque, gingivitis or bleeding compared to BZ. CONCLUSIONS: This study demonstrated that the addition of EO non-alcohol containing mouthrinse to the manual toothbrushing and flossing regimen further reduces plaque, gingivitis and bleeding showing that addition of EO mouthrinses (alcohol or non-alcohol containing) to the oral hygiene regimen provides sustained reductions in plaque to help maintain gingival health after a dental prophylaxis. Dental professional recommendation of the addition of an EO non-alcohol containing mouthrinse to daily oral hygiene routines of brushing or brushing and flossing should be considered to aid supragingival plaque control and improve gingivitis prevention. STUDY REGISTRY NUMBER: NCT05600231.

Effectiveness of different toothbrushing patterns among schoolchildren in an urban area of Argentina.

AIM: To identify toothbrushing patterns among schoolchildren with no prior dental hygiene training and associate them with effectiveness for eliminating dental biofilm. MATERIALS AND METHODS: Eight calibrated dentists assessed dental biofilm, toothbrushing procedure and dental status and registered: grip, bristle angle with respect to tooth, type of movement, surfaces brushed, simultaneous brushing of both jaws, including all six sextants and duration of brushing dental biofilm before and after brushing was determined in 944 children. Frequency distribution was calculated for nominal variables and central tendency and dispersion for quantitative variables of the toothbrushing procedure. Effectiveness was evaluated in 236 children by calculating differences between biofilm levels before and after brushing using Student's test. A cutoff value was established for the difference in reductions in biofilm levels by means of an ROC curve. RESULTS: The variables including all 6 sextants and bristle angle showed positive association with biofilm reduction. The cutoff point for biofilm reduction for including all 6 sextants was 66.85% (OR 6.4 [3.6-11.38]). The cutoff value for biofilm reduction for bristle angle was 68.35% (OR 3.2 [1.83-5.8]). CONCLUSION: The variables associated with biofilm reduction can be used to optimize the modality of future educational interventions in schoolchildren.

Air-polishing followed by ultrasonic calculus removal for the treatment of gingivitis: A 12-month, split-mouth randomized controlled clinical trial.

OBJECTIVE: To evaluate the advantages of a novel protocol involving full-mouth erythritol-powder air-polishing followed by ultrasonic calculus removal in the maintenance of patients treated for gingivitis, with a focus on time and comfort. METHODS: Systemically healthy patients with gingivitis were selected. Following a split-mouth design, quadrants 1-4 and 2-3 were randomly allocated to receive air-polishing followed by ultrasonic calculus removal following a protocol known as Guided Biofilm Therapy (GBT) or traditional full-mouth ultrasonic debridement followed by polishing with a rubber cup and prophylactic paste (US + P). Bleeding on probing (BoP) and the plaque index (PI) were collected at baseline (T0), 2 weeks (T1), 4 weeks (T2), 3 months (T3), and 6 months (T4) and 12 months (T5). Following the same randomization, prophylactic therapy was provided at 3 months (T3) and 6 months (T4). Clinical parameters, treatment time and patient comfort and satisfaction were evaluated. RESULTS: A total of 41 patients were selected, 39 completed the study. The clinical parameters were clinically satisfactory for both treatments at every time. At 4 months after treatment, GBT maintained significantly lower BoP and PI. GBT protocol required a significantly lower treatment time, especially at T3 and T4, when it saved 24.5% and 25.1% of the time, respectively. Both treatments were rated positively by most patients. However, GBT was perceived as more comfortable, and a higher number of patients preferred it. CONCLUSION: No significant difference was observed between GBT and conventional ultrasonic debridement and rubber cup polishing in terms of BoP and PI levels. The GBT protocol allowed less time expenditure and higher patients' perceived comfort.

Cleansing efficacy of an auto-cleaning toothbrushing device with nylon bristles: a randomized-controlled pilot study.

OBJECTIVES: To compare the cleansing efficacy of an auto-cleaning device with nylon bristles (Y-brush®) to that of manual toothbrushing. MATERIALS AND METHODS: Twenty probands refrained from oral hygiene for 3 days. Rustogi Modified Navy Plaque Index was assessed before and after (randomized) toothbrushing either with the auto-cleaning device for 5 s per jaw or with a manual toothbrush for a freely chosen time up to 4 min. The clinical investigation was repeated in a cross-over design. In a third trial period, the brushing time for auto-cleaning was increased to 15 s per jaw. The study was supplemented by plaster cast analyses. RESULTS: Full-mouth plaque reduction was higher with manual toothbrushing than with auto-cleaning for 5 s per jaw (p < 0.001). There was no statistically significant difference on smooth tooth surfaces but on marginal and interdental sites. Increasing the brushing time of auto-cleaning to 15 s per jaw resulted in a comparable full-mouth plaque reduction as with manual toothbrushing (p = 0.177). In 95% of individuals, the device was too short not completely covering second molars. In 30.67% of teeth, the gingival margin was not covered by bristles. CONCLUSIONS: Auto-cleaning devices with nylon bristles have a future potential to reach plaque reduction levels comparable to manual toothbrushing, although manufacturers must focus on improving an accurate fit. CLINICAL RELEVANCE: Under the premise of an ameliorated fit, the auto-cleaning device might be recommendable for people with low brushing efficacy. Interdental sites remain a failure point if adjunct interdental cleaning is not viable.

Changes in Dental Biofilm Proteins' Secondary Structure in Groups of People with Different Cariogenic Situations in the Oral Cavity and Using Medications by Means of Synchrotron FTIR-Microspectroscopy.

This work unveils the idea that the cariogenic status of the oral cavity (the presence of active caries lesions) can be predicted via a lineshape analysis of the infrared spectral signatures of the secondary structure of proteins in dental biofilms. These spectral signatures that work as natural markers also show strong sensitivity to the application in patients of a so-called modulator-a medicinal agent (a pelleted mineral complex with calcium glycerophosphate). For the first time, according to our knowledge, in terms of deconvolution of the complete spectral profile of the amide I and amide II bands, significant intra- and intergroup differences were determined in the secondary structure of proteins in the dental biofilm of patients with a healthy oral cavity and with a carious pathology. This allowed to conduct a mathematical assessment of the spectral shifts in proteins' secondary structure in connection with the cariogenic situation in the oral cavity and with an external modulation. It was shown that only for the component parallel ß-strands in the amide profile of the biofilm, a statistically significant (p < 0.05) change in its percentage weight (composition) was registered in a cariogenic situation (presence of active caries lesions). Note that no significant differences were detected in a normal situation (control) and in the presence of a carious pathology before and after the application of the modulator. The change in the frequency and percentage weight of parallel ß-strands in the spectra of dental biofilms proved to be the result of the presence of cariogenic mutans streptococci in the film as well as of the products of their metabolism-glucan polymers. We foresee that the results presented here can inherently provide the basis for the infrared spectral diagnosis of changes (shifts) in the oral microbiome driven by the development of the carious process in the oral cavity as well as for the choice of optimal therapeutic treatments of caries based on microbiome-directed prevention measures.

Streptococcus salivarius as an Important Factor in Dental Biofilm Homeostasis: Influence on Streptococcus mutans and Aggregatibacter actinomycetemcomitans in Mixed Biofilm.

A disturbed balance within the dental biofilm can result in the dominance of cariogenic and periodontopathogenic species and disease development. Due to the failure of pharmacological treatment of biofilm infection, a preventive approach to promoting healthy oral microbiota is necessary. This study analyzed the influence of Streptococcus salivarius K12 on the development of a multispecies biofilm composed of Streptococcus mutans, S. oralis and Aggregatibacter actinomycetemcomitans. Four different materials were used: hydroxyapatite, dentin and two dense polytetrafluoroethylene (d-PTFE) membranes. Total bacteria, individual species and their proportions in the mixed biofilm were quantified. A qualitative analysis of the mixed biofilm was performed using scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). The results showed that in the presence of S. salivarius K 12 in the initial stage of biofilm development, the proportion of S. mutans was reduced, which resulted in the inhibition of microcolony development and the complex three-dimensional structure of the biofilm. In the mature biofilm, a significantly lower proportion of the periodontopathogenic species A. actinomycetemcomitans was found in the salivarius biofilm. Our results show that S. salivarius K 12 can inhibit the growth of pathogens in the dental biofilm and help maintain the physiological balance in the oral microbiome.

Influence of eight debridement techniques on three different titanium surfaces: A laboratory study.

OBJECTIVES: Debridement methods may damage implant surfaces. This in vitro study investigated eight debridement protocols across three implant surfaces to assess both biofilm removal and surface alterations. MATERIAL AND METHODS: One hundred sixty commercially pure titanium discs were treated to simulate commercially available titanium implant surfaces-smooth, abraded and abraded and etched. Following inoculation with whole human saliva to create a mixed species biofilm, the surfaces were treated with eight debridement methods currently used for clinical peri-implantitis (n = 10). This included air abrasion using powders of glycine, sodium bicarbonate and calcium carbonate; conventional mechanical methods-piezoelectric scaler, carbon and stainless steel scalers; and a chemical protocol using 40% citric acid. Following treatment, remaining biofilm was analysed using scanning electron microscopy and crystal violet assays. For statistical analysis, ANOVA was applied (p < 0.05). RESULTS: All debridement techniques resulted in greater than 80% reduction in biofilm compared with baseline, irrespective of the surface type. Glycine powder delivered through an air polishing system eliminated the most biofilm. Mechanical instruments were the least effective at eliminating biofilm across all surfaces and caused the greatest surface alterations. Citric acid was comparable with mechanical debridement instruments in terms of biofilm removal efficacy. Titanium surfaces were least affected by air abrasion protocols and most affected by mechanical methods. CONCLUSIONS: Mechanical protocols for non-surgical debridement should be approached with caution. Glycine powder in an air polisher and 40% citric acid application both gave minimal alterations across all implant surfaces, with glycine the superior method in terms of biofilm removal.

Effect of high-fluoride dentifrice on root dentine and bacterial composition in a multispecies biofilm model.

The present study evaluated the effect of high-fluoride dentifrice on dentine demineralization and bacterial composition in a multispecies biofilm model in vitro. A seven-organism bacterial consortium was grown on bovine dentine discs in a high-throughput active attachment model. The biofilms were submitted twice per day to the following dentifrices treatments: 5,000 ppm F, 1,100 ppm F, with placebo as a negative control. After 5 days of biofilm growth, dentine samples were assessed by transversal microradiography, the biofilm was collected for bacterial counts and the pH of the media was determined. Lower integrated mineral loss values were observed when 5,000 ppm F-treatment was used compared to the other treatments. Overall microbiological counts decreased with increasing F-concentration as well the pH of the media throughout the experiment. The 5,000 ppm F-treatment caused a shift in microbial composition and reduced dentine demineralization in the in-vitro experimental model.

Effects of free and nano-encapsulated bovine lactoferrin on the viability and acid production by Streptococcus mutans biofilms.

Tooth decay is one of the most common diseases that humans face during their lifetime. Streptococcus mutans is one of the most critical factors of early tooth decay. These bacteria may produce biofilms in the mouth, which are more resistant to antimicrobial agents. Streptococcus mutans may also demineralize tooth enamel by producing lactic acid. In this study, the effect of nanoliposomes containing lactoferrin at three different concentrations (1·5, 3 and 6 mg ml-1 ) on the biofilm formed by S. mutans was investigated. Nanoliposomes were prepared using the thin-layer hydration method. An active attachment model was used to evaluate biofilm and lactic acid production. The results showed that nano-encapsulated lactoferrin could reduce CFU of biofilm more effectively than free lactoferrin. Lactoferrin-containing nanoliposomes also significantly reduced lactic acid production by S. mutans. Therefore, nano-encapsulated lactoferrin may be used along with other dental caries control methods to increase anti-caries efficacy.

In vitro evaluation of the antibacterial effect of four root canal sealers on dental biofilms.

OBJECTIVES: To dynamically evaluate the effect of four root canal sealers on the killing of biofilms within dentinal tubules. MATERIALS AND METHODS: Dentin blocks were prepared for infection of the dentinal tubules. Enterococcus faecalis VP3-181 and multi-species bacteria from two donors were cultured. After 3 days of incubation, the infected dentin specimens were rinsed with sterile water for 1 min and subjected to treatment. Additionally, multi-species bacteria from donor 1 were incubated for 3 weeks to allow biofilm maturation and then the specimens were subjected to treatment. Gutta-percha-treated dentin specimens comprised the control group. A root canal sealer (bioceramic sealers: EndoSequence BC Sealer, ProRoot Endo Sealer, or GuttaFlow Bioseal; and a traditional silicone-based sealer: Guttaflow 2) was spread onto the canal walls of the dentin. The specimens were examined with confocal laser scanning microscopy at 7, 30, or 60 days. RESULTS: In the 3-day-old biofilm group, the proportion of killed bacteria decreased significantly from the first 7 days of treatment to 60 days of treatment for all sealers (p < 0.05). In the 3-week-old biofilm group, 60 days of exposure to bioceramic sealers resulted in more significant dead bacteria than 7-day exposures of the biofilms (p < 0.05). Bioceramic sealers were more effective in killing bacteria than the GuttaFlow 2 sealer (p < 0.05). CONCLUSIONS: Calcium silicate-based sealers showed good antimicrobial effects against biofilms within dentinal tubules, especially in the first week in young biofilms. There is no substantive antibacterial activity observed for the examined root canal sealers against young dentinal tubule biofilms. CLINICAL RELEVANCE: The bioceramic root canal sealers examined demonstrate minimal additional antibacterial effects after long-term exposure to young biofilms.

Effects of xylitol chewing gum and candies on the accumulation of dental plaque: a systematic review.

OBJECTIVES: A systematic review of published data was conducted with the aim of assessing the effects of xylitol consumption on the amount of dental plaque. MATERIALS AND METHODS: Electronic and hand searches were performed to find clinical studies concerning the effects of xylitol chewing gum or candies on dental plaque. Prospective randomized controlled clinical trials published between 1971 and 2020 conducted in healthy subjects were included in the review. RESULTS: The initial search identified 424 xylitol articles. After applying inclusion and exclusion criteria, altogether 14 articles (16 studies) were reviewed. The review identified 12 of the total of 14 xylitol chewing gum studies as having fair or high quality. In 13 of the 14 chewing gum studies, xylitol gum decreased plaque accumulation. In six studies, xylitol gum chewing decreased plaque compared to sorbitol gum, and in three studies compared to gum base/no gum. In three fair-quality studies conducted with xylitol candies, plaque accumulation did not change. CONCLUSIONS: Habitual xylitol gum chewing appears to show plaque-reducing effects that differ from those of sorbitol gum. This suggests specific effects for xylitol on plaque accumulation. Xylitol candies appear not to decrease plaque. The heterogeneity of the studies warrants further research. Clinical relevance Habitual xylitol gum chewing is likely to decrease plaque.

A thermosensitive gel with an active hyaluronic acid ingredient that contains an octenidine preservation system as an adjunct to scaling and root planning: a randomized prospective clinical study.

OBJECTIVES: To evaluate the adjunctive effect of a thermosensitive gel formulation that contains 0.8% oligo hyaluronic acid (HA) combined with a preservation system of octenidine HCl 0.625% and phenoxyethanol to scaling and root planing (SRP) as compared with SRP alone in the treatment of residual pockets of patients with stage 3 periodontitis. MATERIALS AND METHODS: Thirty-four patients (21 males and 13 females) aged 29-78 years (51.3 ± 13.1) with stage 3 periodontitis were recruited to participate in the present split-mouth study. None of the patients has been previously treated for periodontitis. Plaque index (PI), probing depth (PD), clinical attachment level (CAL), and bleeding on probing (BOP) were evaluated at baseline and at 3 and 6 months post treatment. Full-mouth SRP was performed in all residual pockets ≥ 5 mm. Treatment was performed by means of ultrasonic and hand instruments and lasted 45-60 min. The gel was applied subgingivally in the test sites immediately after SRP (baseline) and 1 month later. The paired t-test for two means was applied to test the statistical significance of the change from baseline within each arm and determine the difference between groups. The level of significance was set at 0.05 for all tests. RESULTS: Mean PD reductions between baseline and 3 and 6 months were 1.98 mm and 2.79 mm for the test and 1.22 mm and 1.50 mm for the control group, respectively. Comparisons between the test and control groups revealed that SRP + gel yielded statistically significantly higher PD reductions compared to SRP alone (p < 0.0001). Compared to baseline, CAL and BOP values improved statistically significantly in both groups, although the test group presented statistically significantly higher CAL gains and BOP reductions than the control group (P < 0.0001). CONCLUSION: In residual pockets of stage 3 periodontitis patients, the local application of a thermosensitive gel with an active HA ingredient and a preservation system of octenidine HCl 0.625% in conjunction with SRP may additionally improve the clinical outcomes obtained with SRP alone. CLINICAL RELEVANCE: A novel HA and octenidine containing thermosensitive gel effectively improved the clinical parameters in stage 3 periodontitis patients over a 6-month period.

Clinical evaluation of air polishing with erythritol powder followed by ultrasonic calculus removal versus conventional ultrasonic debridement and rubber cup polishing for the treatment of gingivitis: A split-mouth randomized controlled clinical trial.

OBJECTIVES: To evaluate the clinical efficacy in the short-term resolution of gingivitis of a novel protocol involving full-mouth erythritol powder air polishing followed by ultrasonic calculus removal. METHODS: Forty-one healthy patients completed the study. Following a split-mouth design, quadrants 1-4 and 2-3 were randomly allocated to receive air polishing followed by ultrasonic calculus removal (A+US) or traditional full-mouth ultrasonic debridement followed by polishing with a rubber cup and prophylactic paste (US+P). Bleeding on probing (BoP) and plaque index (PI) were collected at baseline and 2 and 4 weeks. Moreover, the residual plaque area (RPA), treatment time and patient comfort/satisfaction were evaluated at the end of the treatment. RESULTS: Both treatments showed a significant reduction in BoP and PI. At 4 weeks, A+US seems to reach a statistically significant lower BoP (8.7% [6.9; 10.9] vs. 11.6%[9.3; 14.4], p < 0.0001) and PI (10.7% [8.9; 13.0] vs. 12.3% [10.2; 14.9], p = 0.033). Moreover, A+US treatment time lasted on average 9.2% less than US+P (p < 0.0001) and was the preferred treatment for a significantly higher number of patients (73.2% vs. 17.1%, p = 0.0001). CONCLUSION: The A+US protocol is suitable for the short-term resolution of plaque-induced gingivitis.

DYNAMICS OF CHANGES IN THE MICROBIAL PICTURE OF THE ORAL CAVITY ON THE BACKGROUND OF CHRONIC OPIOID EXPOSURE IN THE EXPERIMENT.

OBJECTIVE: The aim is to investigate changes in the microbiota of dental biofilm at the end of the eighth, tenth and twelfth weeks of experimental opioid exposure. PATIENTS AND METHODS: Materials and methods: The study was performed on 36 white outbred adult male rats, which were injected with the opioid analgesic nalbuphine in increasing doses (0,212 - 0,3 mg / kg) during 8, 10 and 12 weeks. Qualitative and quantitative composition of microbiota of dental biofilm was studied using statistical analysis. RESULTS: Results: After eight weeks of opioid exposure, changes in microbiocenosis of dental biofilm of rats were caused by a significant increase in saprophytic and opportunistic microbiota and an appearance of pathogenic species of indicator microbiota with potential periodontopathogenic action. At the end of the tenth week, a significant increase in the quantitative indicators of certain species of opportunistic microbiota and increase in the quantitative composition of pathogenic bacteria were determined. After twelve week of opioid exposure, a significant increase in the quantitative indicators of pathogenic microbiota of dental biofilm was detected. CONCLUSION: Conclusions: Changes in the qualitative and quantitative composition of the microbiocenosis of the dental biofilm at the end of 8, 10 and 12 weeks of opioid exposure were established, they were manifested by a significant increase in the quantitative indicators of certain species of opportunistic microorganisms and a significant increase in pathogenic microbiota in the dynamics, which led to the progression of dysbiotic changes and purulent-inflammatory process in the oral cavity of rats.

Effect of glaze and chlorhexidine on physical and mechanical properties of bis-acryl resin: An in situ study.

BACKGROUND: Temporary prosthesis protects the oral tissues, in addition to providing aesthetic look and masticatory function until a definitive prosthesis is manufactured. OBJECTIVES: To evaluate the effect of glaze and 0.12% chlorhexidine (CHX) on the physical and mechanical properties of bis-acryl, and to evaluate the antimicrobial efficacy of CHX. MATERIAL AND METHODS: Eighty specimens of bis-acryl resin were made. Over 40 of them the glaze was applied. One specimen with and 1 specimen without glaze were placed in niches of an appliance manufactured for each patient. Each of the 20 volunteers received 2 devices. Initially, the volunteers used one device and treated it with sucrose for 7 days (control), and later they used the other device and treated it with sucrose and CHX for 7 days (test). Color, microhardness, roughness, surface energy, and insoluble extracellular polysaccharides (EPS) tests were performed. All results were submitted to the Tukey's test, with the exception of the EPS results, which were submitted to the Student's t test. RESULTS: The ΔE00 of the unglazed control group was significantly higher than that of the unglazed test group. In all groups, a significant decrease in microhardness occurred over time. At both times, the glaze significantly increased the microhardness of the specimens (in all the glazed groups). At the final time, the test glaze group showed significantly higher microhardness compared with the control glaze group. Roughness in the groups without glaze increased significantly with CHX treatment over time. At both times, the glaze generated a significant reduction in roughness in the control and test groups. There was a significant reduction in surface energy over time in all groups. In most comparisons, the glazed groups showed significantly higher surface energy values compared with the unglazed control group. At the final time point, the unglazed test group showed a significantly higher surface energy value than the unglazed control group; and the glazed test group showed a significantly higher surface energy value compared with the glazed control group. The resins that received CHX had a significantly lower amount of biofilm. CONCLUSIONS: Color values were clinically acceptable in all tested groups. At both time points, the roughness values were clinically acceptable only in the glazed groups. Glaze increased the microhardness of the specimens. Microhardness and surface energy were reduced over time in all groups. Chlorhexidine can help prevent microhardness degradation. Glaze and CHX can increase surface energy. Chlorhexidine reduced the amount of bacterial biofilm.

Affordable oral health care: dental biofilm disruption using chloroplast made enzymes with chewing gum delivery.

Current approaches for oral health care rely on procedures that are unaffordable to impoverished populations, whereas aerosolized droplets in the dental clinic and poor oral hygiene may contribute to spread of several infectious diseases including COVID-19, requiring new solutions for dental biofilm/plaque treatment at home. Plant cells have been used to produce monoclonal antibodies or antimicrobial peptides for topical applications to decrease colonization of pathogenic microbes on dental surface. Therefore, we investigated an affordable method for dental biofilm disruption by expressing lipase, dextranase or mutanase in plant cells via the chloroplast genome. Antibiotic resistance gene used to engineer foreign genes into the chloroplast genome were subsequently removed using direct repeats flanking the aadA gene and enzymes were successfully expressed in marker-free lettuce transplastomic lines. Equivalent enzyme units of plant-derived lipase performed better than purified commercial enzymes against biofilms, specifically targeting fungal hyphae formation. Combination of lipase with dextranase and mutanase suppressed biofilm development by degrading the biofilm matrix, with concomitant reduction of bacterial and fungal accumulation. In chewing gum tablets formulated with freeze-dried plant cells, expressed protein was stable up to 3 years at ambient temperature and was efficiently released in a time-dependent manner using a mechanical chewing simulator device. Development of edible plant cells expressing enzymes eliminates the need for purification and cold-chain transportation, providing a potential translatable therapeutic approach. Biofilm disruption through plant enzymes and chewing gum-based delivery offers an effective and affordable dental biofilm control at home particularly for populations with minimal oral care access.

Effect of drops containing Lactobacillus reuteri (DSM 17938 and ATCC PTA 5289) on plaque acidogenicity and other caries-related variables in orthodontic patients.

BACKGROUND: The purpose of the study was to investigate the effect of probiotics on biofilm acidogenicity and on the number of salivary Streptococcus mutans and lactobacilli in orthodontic patients. METHODS: This RCT was conducted on 28 young adults who were undergoing orthodontic treatment. The short-term prospective clinical trial lasted for three weeks. The test group rinsed daily with drops containing two Lactobacillus reuteri strains diluted in water, while the placebo group used drops without probiotics. The subjects were enrolled eight months since the beginning of orthodontic treatment. Plaque-pH, saliva and dental biofilm samples were obtained at baseline, one week and three weeks post intervention. RESULTS: Twenty-seven subjects successfully completed the trial period, only one drop out in the test group. No side effects were reported. A statistically significant increase in plaque pH at three weeks post-intervention was found for the test group (p < 0.05), while insignificant changes in the pH value were found for the placebo group in comparison to baseline (p > 0.05). In addition, the AUC7.0 showed a significant difference at three weeks between the test and placebo (p = 0.00002). The three-week samples of stimulated whole saliva showed a statistically insignificant difference in the number of S. mutans and lactobacilli between the two groups (p > 0.05). The qPCR analysis showed the ability of the two strains to get colonized in the dental biofilm without a significant effect on the microbial counts. CONCLUSION/CLINICAL IMPLICATIONS: A mixture of Lactobacillus reuteri has the ability to reduce the pH fall at the three-week follow-up. However, the short-term use of probiotics does not appear to have an effect on the number of salivary Streptococcus mutans and lactobacilli in saliva and on the dental biofilm. TRIAL REGISTRATION: Clinicaltrial.gov (Identifier: NCT04593017 / (19/10/2020)).